1. Field of the Invention
One disclosed aspect of the embodiments relates to a technique of manufacturing a detection device that is applied to, e.g., a medical imaging diagnostic apparatus, a nondestructive inspection apparatus, and an analyzing apparatus using radiation. One disclosed aspect of the embodiments further relates to the detection device and a detection system.
2. Description of the Related Art
Recently, the thin-film semiconductor manufacturing technique has been utilized in the field of detection devices of the type including a pixel array in which switch elements, e.g., TFTs (thin film transistors), and conversion elements, e.g., photodiodes, for converting radiation or light to electric charges are combined with each other.
A related-art detection device disclosed in International Publication WO2007/01357 includes conversion elements disposed on electrodes, which are arrayed on a substrate, are isolated for each of pixels, and are made of a transparent conductive oxide. The related-art detection device further includes switch elements connected to the electrodes through contact holes formed in an interlayer insulating layer, which is disposed between the substrate and the electrodes and which is made of an organic material. Impurity semiconductor layers and semiconductor layers of the conversion elements are partly removed on the interlayer insulating layer such that the conversion elements are isolated per pixel.
In trying to manufacture the detection device disclosed in International Publication WO2007/01357, however, a manufacturing method includes an operation where the interlayer insulating layer is brought into an exposed state when an impurity semiconductor film becoming an impurity semiconductor layer of the conversion element later is formed. In some cases, therefore, the surface of the interlayer insulating layer is exposed when the impurity semiconductor film is formed. Accordingly, an organic material of the interlayer insulating layer may be partly scattered and mixed into the impurity semiconductor layer depending on the type of film forming process. This raises the problem that the impurity semiconductor layer of the conversion element is organically contaminated, and that defects in the impurity semiconductor layer and defects at the interface between the impurity semiconductor layer and the semiconductor layer are increased, whereby a dark current in the conversion element is increased.
To prevent the interlayer insulating layer from being exposed, an insulating layer made of an inorganic material may be disposed over the interlayer insulating layer. In such a case, however, the electrode of the conversion element, the electrode being made of the transparent conductive oxide, is disposed on the insulating layer. The transparent conductive oxide is formed through polycrystallization after forming it in an amorphous state. Internal stress in the transparent conductive oxide is changed during the polycrystallization. Because the insulating layer made of the inorganic material is harder than the interlayer insulating layer made of the organic material and has higher binding energy, a problem may occur in that the insulating layer cannot follow the change of the internal stress during the polycrystallization of the transparent conductive oxide and the electrode of the conversion element is peeled off from the insulating layer.